the USMC on 16 May 2018; at the time, 18 additional helicopters were in production, and the second was planned for delivery in early 2019. In December 2018, the CH-53K was projected to not be combat ready as expected in late 2019, due to delivery delays caused by technical flaws found in testing, which resulted in a major program restructuring. Flaws included the engine re-ingesting exhaust gas, limited service life for the rotor gear boxes, late deliveries of redesigned parts, and deficiencies with the tail rotor and driveshaft. It is estimated that the delay will push back delivery of combat-ready CH-53Ks until May 2020. Design The CH-53K King Stallion is a heavy lift helicopter, being a general redesign of the preceding CH-53E, the main improvements being the new engines and cockpit layout. It has over twice the lift capacity and radius of action of the CH-53E, and a wider cargo hold to allow it to carry a Humvee internally. A new composite rotor blade system is also used, featuring technology similar to that of the UH-60 Black Hawk helicopter. The CH-53K is powered by the General Electric GE38-1B engine, which was selected over the Pratt and Whitney Canada PW150 and a variant of the Rolls-Royce AE 1107C-Liberty used on the V-22 Osprey. Each of the three T408 engines is rated at , and gives the CH-53K the ability to fly faster than its CH-53E predecessor. The CH-53K features a new digital glass cockpit with fly-by-wire controls and haptic feedback, HUMS, a new elastomeric hub system, and composite rotor blades to improve "hot and high" performance. The split torque gearbox with quill shafts started development around 2007. The gearbox assembly including rotor hub and rotating control system weighs around . The split torque gearbox weighs . For comparison, the twin-engine Mil Mi-26's split torque gearbox weighs . The CH-53K has an improved external cargo handling system, survivability enhancements, and improvements to extend service life. The cabin will be long by wide by tall. Its cabin will be wider and 15% larger, but will have new shorter composite sponsons. The CH-53K can carry two 463L master pallets, eliminating the need to break apart pallets between airlifter and helicopter. The CH-53K is to surpass the capability of its predecessor by carrying nearly 30% more than the CH-53E's external payload of over the same radius of . The CH-53K's payload reaches a maximum of